Conditions for through-process analysis of product surface in steel manufacture

Abstract

In the steel industry, there is a trend to equip an increasing number of production lines with camera-based inspection systems to monitor the surface quality of the steel. These systems are dedicated to automatically detect and classify surface defects. When camera systems are used in different processing lines through which the steel subsequently passes, it becomes possible to track the surface quality through the chain. Linking through-process data enables fast root cause analysis and optimisation of manufacturing practice to minimise the defect level. The evaluation of the changes in surface condition through the process is hampered by problems in data synchronisation, changes in product geometry (scaling), parts of the product that are taken out of the process chain (slit edges, cut off heads or tails) and delays in the processing chain (e.g. due to the maintenance of a production line). This paper highlights the conditions and problems encountered in integrated process analysis in an industrial environment.